A very high energy gamma‐ray spectrum of 1es 2344+514
| Autor: | D. Horan, John L. Quinn, G. H. Gillanders, M. Kertzman, Jeffrey Zweerink, D. J. Fegan, S. P. Wakely, M. J. Lang, K. Kosack, S. Fegan, John Kildea, H. Sembroski, David Kieda, V. V. Vassiliev, G. B. Power-Mooney, Mark N. Quinn, J. P. Finley, M. Schroedter, T. C. Weekes, H. M. Badran, K. Lee, G. E. Kenny, J. H. Buckley, F. Krennrich, J. Bussons Gordo, P. Moriarty, J. Grube, C. Duke, D. A. Carter-Lewis |
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| Rok vydání: | 2005 |
| Předmět: |
tev energies
Infrared Point source bl-lacertae objects FOS: Physical sciences Astrophysics bl lacertae objects : individual (1es 2344+514) gamma rays : observations active galaxy markarian-421 einstein slew survey host galaxies 1es 2344+514 cherenkov telescopes imaging technique pks 2155-304 crab-nebula Spectral line Blazar Physics Spectral index markarian 421 Astrophysics (astro-ph) Gamma ray HEGRA Astronomy and Astrophysics Redshift Space and Planetary Science |
| Zdroj: | Department of Physics and Astronomy Faculty Publications |
| Popis: | The BL Lacertae (BL Lac) object 1ES 2344+514 (1ES 2344), at a redshift of 0.044, was discovered as a source of very high energy (VHE) gamma rays by the Whipple Collaboration in 1995 \citep{2344Catanese98}. This detection was recently confirmed by the HEGRA Collaboration \citep{2344Hegra03}. As is typical for high-frequency peaked blazars, the VHE gamma-ray emission is highly variable. On the night of 20 December, 1995, a gamma-ray flare of 5.3-sigma significance was detected, the brightest outburst from this object to-date. The emission region is compatible with a point source. The spectrum between 0.8 TeV and 12.6 TeV can be described by a power law $\frac{\ud^3 N}{\ud E \ud A \ud t}=(5.1\pm1.0_{st}\pm1.2_{sy})\times10^{-7} (E/ \mathrm{TeV})^{-2.54 \pm0.17_{st}\pm0.07_{sy}} \mathrm{\frac{1}{TeV m^2 s}}$. Comparing the spectral index with that of the other five confirmed TeV blazars, the spectrum of 1ES 2344 is similar to 1ES 1959+650, located at almost the same distance. The spectrum of 1ES 2344 is steeper than the brightest flare spectra of Markarian 421 (Mrk~421) and Markarian 501 (Mrk~501), both located at a distance about 2/3 that of 1ES 2344, and harder than the spectra of PKS 2155-304 and H~1426+428, which are located almost three times as far. This trend is consistent with attenuation caused by the infrared extragalactic background radiation. 27 pages, 11 figures, accepted by ApJ |
| Databáze: | OpenAIRE |
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